.40 Smith and Wesson

The .40 S&W (10×22mm Smith & Wesson in unofficial metric notation) is a rimless pistol cartridge developed jointly by major American firearms manufacturers Smith & Wesson and Winchester. The .40 S&W was developed from the ground up as a law enforcement cartridge designed to duplicate performance of the Federal Bureau of Investigation’s (FBI) reduced-velocity 10mm Auto cartridge which could be retrofitted into medium-frame (9mm size) semi-automatic handguns. It uses 0.40-inch (10 mm) diameter bullets ranging in weight from 105 to 200 grains (6.8 to 13.0 g). [Wikipedia]